In the industrial production of textile articles, such as carpet and apparel, and such other fibrous substrates as paper and leather, it is common to treat such substrates with fluorochemicals containing fluoroaliphatic radicals (often designated by the symbol "R.sub.f ") to impart oil and water repellency to the surface of such substrates. Fluorochemicals of this type and their application to fibrous substrates are described in various prior art publications, e.g., U.S. Pat. Nos. 3,329,661 (Smith et al), 3,398,182 (Guenthner et al), 3,458,571 (Tokoli), 3,574,791 (Sherman et al), 3,728,151 (Sherman et al), 3,916,053 (Sherman et al), 4,144,367 (Landucci), 3,896,251 (Landucci), 4,024,178 (Landucci), 4,165,338 (Katsushima et al), 4,190,545 (Marshall), 4,215,205 (Landucci), 4,013,627 (Temple), 4,264,484 (Patel), 4,426,476 (Chang), 4,029,585 (Dettre), 3,462,296 (Raynolds et al), 4,401,780 (Steel), 4,325,857 (Champaneria et al), and Banks, R. E., Ed. "Organofluorine Chemicals and their Industrial Applications", Ellis Horwood, Ltd., West Sussex, England 226-230 (1979).
Although some fluorochemicals are useful in many applications and many are commercial products, some are relatively expensive to prepare and apply, others are difficult to apply, and others are not durable or do not impart the required properties to the extent desired.
Conventionally, fluorochemical compositions are applied to fibrous substrates, e.g., textiles and textile fiber, as solutions in organic solvents or as aqueous emulsions, as described in the above cited references, e.g., U.S. Pat. Nos. 3,329,661 and 4,024,178.
It is an object of this invention to provide a fluorochemical biuret and method for its preparation.
Another object of this invention is to provide fluorochemical biurets, including anionic and cationic derivatives thereof, useful for treating porous substrates, such as carpet fibers and carpet, for imparting oil, water and stain resistance thereto.
A further object of this invention is to provide fluorochemical biurets in the form of stable emulsions, microemulsions and dispersions useful for the treatment of porous substrates, such as fibers, paper, leather and the like to impart oil, water and stain resistance thereto.
A still further object of this invention is to provide blends of fluorochemical biurets and fluorochemical poly(oxyalkylenes), which blends can be used in the form of aqueous dispersions, emulsions and microemulsions to treat fibrous substrates such as textile fibers, filaments, yarns, or finished fibrous articles, such as carpet, and other fibrous substrates such as paper and leather, to impart oil and water repellency and stain resistance thereto.